Many mechanisms have been developed for wrapping bales with netwrap, which is a sheet material typically in the form of light, very thin web material. Examples that utilize feed rollers are disclosed in R. M. Van Ginhoven et al U.S. Pat. No. 4,366,665; C. Clostermeyer et al U.S. Pat. No. 4,599,844; Krone et al U.S. Pat. No. 4,604855; H. D. Antsey et al U.S. Pat. No. 4,697,402; J. L. Raes U.S. Pat. No. 4,729,213; DE 92 11 541; and J. H. Merritt U.S. Pat. No. 4,729,213 and commonly assigned Van Zee U.S. Pat. No. 5,129,208. The use of feed rollers to feed this light, unstable material has inherent limitations. A mechanism that does not utilize feed rollers is disclosed in Underhill U.S. Pat. No. 5,036,642. It is particularly adapted for feeding the netwrap into the front of a round baler. Another mechanism that does not utilize feed rollers, and is adapted for feeding netting into the rear portion of a baler is disclosed in Van den Wildenberg EP 0 820 691.
The supply roll of the netting material is known to be wider than the length of the cylindrical bale. Mechanisms have been developed to improve the feeding of this wide netwrap material. One early example is shown in Van den Wildenberg U.S. Pat. No. 4,917,008. Later mechanisms, to more reliably wrap the netwrap material around the edges of the bale, are disclosed in McClure et al. U.S. Pat. No. 6,550,218 and Myers et al. U.S. Pat. No. 6,006,504. The mechanism disclosed in Myers includes an element that interacts with the formed bale and cooperates with the lower idler roller that defines the net entry point, to provide space for entry of the outer edge of the netting material into the baler such that the outer edge does not contact the bale until some distance from the idler roller. The use of such an element, located near a roller at the bottom of a baler, was previously known, as disclosed in Meyer U.S. Pat. No. 4,910,949 as a wedge member that interacts with the formed bale to affect the sides of the bale.
In addition to feeding the material to the baler, the netwrap mechanism must sever the material, after the desired amount of netwarp has been dispensed. The Van den Wildenberg reference discloses a cutting mechanism comprising several moving parts that must work together to cut the netwrap.